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charset="UTF-8" Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Sep 9, 2020 at 11:16 AM Ritesh Harjani wrote: > > If we hit the UINT_MAX limit of bio->bi_iter.bi_size and so we are anyway > not merging this page in this bio, then it make sense to make same_page > also as false before returning. > > Without this patch, we hit below WARNING in iomap. > This mostly happens with very large memory system and / or after tweaking > vm dirty threshold params to delay writeback of dirty data. > > WARNING: CPU: 18 PID: 5130 at fs/iomap/buffered-io.c:74 iomap_page_release+0x120/0x150 > CPU: 18 PID: 5130 Comm: fio Kdump: loaded Tainted: G W 5.8.0-rc3 #6 > Call Trace: > __remove_mapping+0x154/0x320 (unreliable) > iomap_releasepage+0x80/0x180 > try_to_release_page+0x94/0xe0 > invalidate_inode_page+0xc8/0x110 > invalidate_mapping_pages+0x1dc/0x540 > generic_fadvise+0x3c8/0x450 > xfs_file_fadvise+0x2c/0xe0 [xfs] > vfs_fadvise+0x3c/0x60 > ksys_fadvise64_64+0x68/0xe0 > sys_fadvise64+0x28/0x40 > system_call_exception+0xf8/0x1c0 > system_call_common+0xf0/0x278 > > Fixes: cc90bc68422 ("block: fix "check bi_size overflow before merge"") > Suggested-by: Christoph Hellwig > Reported-by: Shivaprasad G Bhat > Signed-off-by: Anju T Sudhakar > Signed-off-by: Ritesh Harjani > --- > RESEND: added "fixes" tag > > block/bio.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/block/bio.c b/block/bio.c > index a7366c02c9b5..675ecd81047b 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -877,8 +877,10 @@ bool __bio_try_merge_page(struct bio *bio, struct page *page, > struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1]; > > if (page_is_mergeable(bv, page, len, off, same_page)) { > - if (bio->bi_iter.bi_size > UINT_MAX - len) > + if (bio->bi_iter.bi_size > UINT_MAX - len) { > + *same_page = false; > return false; > + } > bv->bv_len += len; > bio->bi_iter.bi_size += len; > return true; Reviewed-by: Ming Lei -- Ming Lei